Age-related changes in the retina and retinal pigment epithelium (RPE) have been characterized using morphological and biochemical techniques. One of the major age-related changes in the RPE is the progressive accumulation of lipofuscin, or age-pigment. We have continued experiments to elucidate factors which might play a role in RPE lipofuscin accumulation. Dietary deficiency in retinol was found to result in a reduced amount of lipofuscin deposition in the RPE. Excess dietary retinol also reduced the amount of RPE lipofuscin deposition in vitamin E-sufficient rats, but not in vitamin E-deficient rats. Phagocytosis by the RPE was also found to play a significant role in RPE lipofuscin accumulation. RCS rats with hereditary retinal degeneration were found to accumulate much less RPE lipofuscin than did congenic control animals whose retinas did not undergo degeneration. In addition to lipofuscin accumulation, a number of other age-related changes in the retina and RPE have been examined. Retinal capillary basement membranes in both the outer plexiform and ganglion cell layers were found to thicken during aging, retinal cell death accompanied senescence, and vitamin A metabolism in the retina-RPE complex was altered during aging.